Interesting. If I do build an helo with 2 Blades and an helo with 5 Blades of the same shape as the 2 bladed one, that changes nothing.
let's hear it for rotor solidity ratio........ how many helicopters with a small, two-bladed system do you see?
Sokol - yes scale is an issue with wind tunnels but quite a well understood one - have you studied Reynolds numbers?